Make sure you change your TV audio OUT setting to "External Speakers" (if using RCA Audio OUT ) or "Headset" (if using AUX/3.5mm OUT).

RCA:3.5mm:

Note : Plug a wired ear buds into the TV headphone jack or RCA audio out (via an adapter), check if you can hear sound. If no sound, then the TV is not outputing the right signal now.

2. Optical Connection

1)Ensure your TV audio format is set to “PCM” or "DOLBY/DTS" is OFF. For how to, refer to How to set TV Audio Format/PCM. If you have other TV models, you can google "TV Brand, TV model, audio output". Or you can contact TV manufacture for reliable support. Check the contact info at the end.